As a solid-state imaging device which is mounted on a digital still camera, or a digital video camera, a CMOS image sensor (hereinafter, abbreviated to CIS) has been known. In addition, there is a case in which the CIS is used in an imaging apparatus for sensing, and in a case of such a use, rapidity of operations is particularly necessary.
For acceleration of operations of the CIS, a method in which an AD conversion unit (hereinafter, abbreviated to ADC) is provided to one, or a relatively small number of pixels, and a plurality of the ADCs are operated in parallel has been known.
In such a method, optical characteristics of pixels are sacrificed when providing the ADC in the same substrate of the pixel.
Therefore, a configuration in which pixels and ADCs are provided on separate substrates, and both of the substrates are connected by being bonded using Cu—Cu bonding in order not to sacrifice optical characteristics of the pixels has been proposed. In addition, since a size of one ADC usually corresponds to a size of a plurality of pixels, the plurality of pixels on the separate substrate are correspondingly connected to the one ADC (for example, refer to PTL 1).
FIG. 1 illustrates a conceptual diagram when a pixel block which is configured by 16 pixels of 4*4 pixels in total is correspondingly connected to one ADC on a separate substrate. In the figure, a rectangle of a thin line denotes a pixel, a thick line denotes a pixel block which is correlated with one ADC, numbers denote positions of pixels, and arrows denote scanning order of pixels. In addition, a pixel which is located on an X row and a Y column is described as a pixel (X, Y).
For example, in a pixel block of which a pixel (0,0) is on the upper left top, scanning is started in the right horizontal direction by setting a pixel on the lower left (3,0) as a starting point, and a row to be scanned is moved in the upper vertical direction sequentially, and an upper right pixel (0,3) is lastly read out. Similarly, in a right neighbor pixel block of the pixel block, scanning is started in the right horizontal direction by setting a pixel on the lower left (3,4) as a starting point, and a row to be scanned is moved in the upper vertical direction sequentially, and an upper right pixel (0,7) is lastly read out.
That is, in each pixel block, a pixel on the lower left is set to a starting point, scanning is started in the right horizontal direction, a row to be scanned is moved in the upper vertical direction sequentially, and a pixel on the upper right is lastly read out.